If you want to contribute, take a look at the issues. Contribution workflow is a standard fork and pull. General Skulpt contribution tutorial can be found here, and the coding style guide here.
In addition to your functionality, make sure to add a unit test into the test directory.
If adding a functionality that is to be tested by running an example, you can add a Pygame program that exposes it.
A good example is test/tick_clock.py.
Otherwise, you can make use of the unittest library as in test/version_test.py.
You might find useful to run the test using the index page. All you have to do is to run it with a query string representing
the filename of your test.
http://localhost:8888/index.html?tick_clock.py